This invention relates to a process for preparing an injectable fluorocarbon emulsion capable of carrying oxygen which may be administered to mammals suffering from severe blood loss.
Prior procedures in the treatment of blood loss of patients in which the blood volume has been reduced by no more than 1500 ml include administration of an injectable liquid, having a colloidal osmotic pressure, for example, dextran, or an electrolyte solution such as Lactate Ringer's solution, thereby to prevent shock caused from the bleeding. These materials are known generally as plasma expanders. However, in the event that the bleeding exceeds 1500 ml in volume, the amount of oxygen carried by red blood-cells in the remaining blood becomes rapidly depleted, and tissue respiration, at least at the peripheral tissues, becomes insufficient. Therefore, loss exceeds about 1500 ml volume expanders, such as dextran or electrolyte solutions are ineffective and a blood transfusion is required.
Preparations having an ability to carrying oxygen in laboratory animals have been studied by a number of investigators, but not until recently has it been known that such preparations could have a potential life saving effect when injected into such animals. In 1966, L. C. Clark Jr. as described in Science, 152 1755 (1966) succeeded in keeping mice living for a relatively long period of time by immersing the mice in certain types of fluorocarbon solutions, and studies on utilization of fluorocarbons as an oxygen carrier in living bodies were started at that time. In 1968, R. P. Geyer reported that total blood of a mouse was exchanged with a fluorocarbon emulsion by blood transfusion and the mouse could be kept living for a few hours, this work is described in "Organ Perfusion and Preservation", Appleton-Centry Crafts, page 85 (1968). Later Clark et al. reported in Chemical and Engineering News, Dec. 15 (1969), page 51 that total blood volume of a dog was exchanged with a fluorocarbon emulsion by blood exchange transfusion, and the dog could be successfully kept living for a relatively long time.
We have now made studies and found a process for preparing an injectable preparation having the ability to carry oxygen, and have found a novel process for preparing, on a mass-production scale, an injectable oxygen-carrying emulsion capable of keeping mammals such as dogs and monkeys living for a long period of time by blood exchange transfusion.
Accordingly it is an object of the present invention to provide a process for preparing an injectable emulsion having the ability to carry a significant amount of oxygen.
Another object of the present invention is to provide a process for preparing, on a mass-production scale, an injectable emulsion capable of keeping mammals such as dogs and monkeys living for a long time by blood exchange transfusion.
Another object of the present invention is to provide a process for preparing a fluorocarbon emulsion applicable as an "artificial blood" and organ perfusate.
Other objects and advantages of the present invention will be apparent from the following description.